rbd: add support for CloneImageByID()

RBD image groups can be used to create consistent snapshots of all
images that are part of the group. The new rbd_clone4() API makes it
possible to create a new RBD image from a single snapshot that was
created as part of the group snapshot.

Signed-off-by: Niels de Vos <ndevos@ibm.com>

Author: nixpanic

rbd/clone_squid.go

@@ -0,0 +1,45 @@
+//go:build !(nautilus || octopus) && ceph_preview
+
+package rbd
+
+// #cgo LDFLAGS: -lrbd
+// #include <errno.h>
+// #include <rados/librados.h>
+// #include <rbd/librbd.h>
+import "C"
+
+import (
+	"unsafe"
+
+	"github.com/ceph/go-ceph/rados"
+)
+
+// CloneImageByID creates a clone of the image from of snapshot with the given
+// ID in the provided io-context with the given name and image options.
+//
+// Implements:
+//
+//	int rbd_clone4(rados_ioctx_t p_ioctx, const char *p_name,
+//	               uint64_t p_snap_id, rados_ioctx_t c_ioctx,
+//	               const char *c_name, rbd_image_options_t c_opts);
+func CloneImageByID(ioctx *rados.IOContext, parentName string, snapID uint64,
+	destctx *rados.IOContext, name string, rio *ImageOptions) error {
+
+	if rio == nil {
+		return rbdError(C.EINVAL)
+	}
+
+	cParentName := C.CString(parentName)
+	defer C.free(unsafe.Pointer(cParentName))
+	cCloneName := C.CString(name)
+	defer C.free(unsafe.Pointer(cCloneName))
+
+	ret := C.rbd_clone4(
+		cephIoctx(ioctx),
+		cParentName,
+		C.uint64_t(snapID),
+		cephIoctx(destctx),
+		cCloneName,
+		C.rbd_image_options_t(rio.options))
+	return getError(ret)
+}